HOUSTON – Chris Carter probably doesn't know what he's done. And he surely doesn't care.

Carter, the powerful Astros designated hitter, walloped two home runs Tuesday night off Twins starter Yohan Pino, almost certainly consigning the 30-year-old rookie back to Class AAA Rochester after 10 big-league starts. "He's in the rotation," manager Ron Gardenhire insisted after a 10-4 loss, but that probably won't be true once the Twins return home.

Then again, Gardenhire didn't exactly sound convinced that Trevor May, who stands to inherit the starting spot, is ready to throw strikes, record outs and win games. May received a second look Tuesday once Pino was pulled, and while it wasn't the avert-your-eyes catastrophe of his weekend debut, it wasn't Bob Feller, either.

"You've got to throw the ball over the plate. He's not commanding his fastball right now," Gardenhire said after May faced 11 batters, retired six of them, walked a couple, and surrendered three runs. "When he gets his next start, hopefully he'll have figured something out."

That next start is scheduled for Monday in Target Field, assuming the Twins don't have second thoughts. But if May's first couple of outings haven't inspired confidence, neither did Pino, which is why his roster spot will probably be turned over to Ricky Nolasco when the veteran righthander returns from his elbow injury on Friday.

"I don't know anything about that," Pino said of his job security. "I want to get back to work. They know what they're doing. There's nothing you can do about that."

Pino's status was shaky anyway, after posting a 4.59 ERA in his first nine starts, and his outing — seven runs in 4⅓ innings, plus three home runs — hardly appeared job-saving. He pitched well for two innings, but the last 14 batters he faced collected seven hits.

The loudest of them belonged to Carter, who slammed a homer off Tommy Milone on Monday, too, and now is just one home from his career high and two away from becoming the first Astros player to hit 30 since Carlos Lee in 2007.

Pino whiffed Carter in the first inning, but the slugger was ready for him in the third, launching an 89-mile-per-hour fastball off an advertising sign high above the seats in left field, a two-run blast. Two innings later, with Pino already trailing 4-1, Carter finished off the righthander, nailing a first-pitch slider and lining it to the front row of the Crawford Boxes in left-center. That was a three-run homer — giving Carter six multi-home run games this season — and ended Pino's night.

The lopsided score gave the Twins a chance to use May, in hopes of boosting his confidence after his seven-walk debut in Oakland. And while it was better, it wasn't, Gardenhire said, major league quality yet.

"The first thing you have to do here is command your fastball. You have to throw it in and out," Gardenhire said. "And up to this point, he hasn't."

May pitched the sixth, and needed 21 pitches to get through it, giving up two runs on three hits. He went to a 3-2 count on his first batter, then threw a fastball out of the strike zone that Matt Dominguez mercifully swung at, grounding out and setting a better tone for the rookie.

A double and two singles produced the runs, but May struck out Grossman on another 3-2 pitch — a 92-mph fastball at the knees — to record his first career strikeout. And in the seventh inning, May needed just eight pitches to retire the side.

Then he walked the first two hitters he faced in the eighth, and after getting a ground ball, he was pulled, too. May gave up three runs over 2⅓ innings, which actually dropped his ERA to 12.46.

"It's better than the first time, but I've still got a long way to go," May said. "I've got to establish strikes early in counts, execute pitches. I executed more than last time, but not nearly as many as I need to."

He's got six days to fix it.